JSP程序运行问题，求大神指点

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">



Insert title here


<%!double a,b,c;
double x1,x2;
double i;
%>
<% a=1;b=-2;c=1;
i=b*b-4*a*c;
%>
<%
x1=(-b+Math.sqrt(i))/(2*a);
x2=(-b+Math.sqrt(i))/(2*a);
%>

x1的值为 <%=x1 %>

x2的值为 <%=x2 %>



代码运行一开始运行是对的，后面运行的时候就弹出一个红叉的对话框显示
The archive: J:/JSP工具/jsp-dev-tools/jsp-dev-tools/apache-tomcat-7.0.26/bin/bootstrap.jar which is referenced by the classpath, does not exist.求大神帮忙

环境问题，貌似是bootstrap.jar这个引用的jar包不存在。看看该包是否存在于上面的路径下